Thermoregulator.



W. .L SMITH.

TBBBMORBGULATOR.

Patented Dec. 2; 1913.

ArPLIoA'rIoN FILED :um: a'o, 1,911.

Patented Dec. 2, 1913.

2 SHEETS-SHEET 2,

UNITED 'STATES PATENT our-ion WILLIAM J. SMITH, or URBANA, ILLINoIs.

THERMOBEGULATOR.

Specicationnf Letters Patent.

Patented Dec. 2, 1913.

Application l'ed June 30, 1911. Serial No. 636,193.

l'of my present invention includes an electric heater', and means for automatically switching current` on and off at'the, proper times to maintain the temperature constant. The automatic means includes a@ thermostat 'which is exposed to heat from said heater and also includes a relay of improved form which is'aetuated by said thermostat and serves to produce the necessary movement of the switch mechanism. The 'circuits of the system are so arranged that the thermostat and its .coperating relay are. supplied by current carried through a circuit which shunts the main or heatingA circuit of the system.

' Also' thel invention includes certain de-A tails and special arrangements of part-s whereby the current through the relay is interrupted after each movement of the switch, all-oil? which is disclosed in detail in the following description which is to be taken in conjunction with'the accompanying drawings.

In the drawings, Figure 1 is an elevation of the' relay and some of the elements which coperate therewith, illustrating diagram'- matically the arrangementof the electrical circuit. Fig. 2 is al perspective view of a portion of the main switch and the armature whereby that' switch is manipula-ted. Fig. 3

`is a perspective view vet an armature 'which serves jas Ia means for holding the main switch in closed position. Fig. 4 is a diagrammatic representation of a system somewhat different from that of Fig. 1.

In the construction shown, the device comprises a box 1, having therein a vertical panel 2 of insulating material which carries at its top' a ,cross piece 3 whereon two lamp sockets et and 5 are mounted. Y

Current may be supplied to the system through distributing conductors 6 and 7 and this currentV may-'pass directly through the heating resistance 8 by way of a main switch which' comprises spring clips 9 and 10 and al wedge shaped member 11.. The member 11 is movable in contact with clips 9 and 10 to establish connection therebetween. Fig. 2 shows one of these clips on an enlarged scale. j

Heater 8 constitutes the work circuit of the system and is the heater whereby the oven, incubator or other chamber is heated to the desired temperature. Located in cooperative relation with said heater 8 is a thermostat 12 of the usual expansion type, the movable member of which is connected current directly fromd the distributing conductor 7. The other two contacts or terminals 13 and 14 of the thermostat are electrically connected with a rela-y serviceable for throwingthe contact member 11 of the main switch.

rI`he relay, whereby the main switch is cont-rolled oroperated, includes an electromotive device which comprises a Winding with that side of resistance 8 which receives 15 arranged horizontally across the tace of panel 2 and having an iron core which', when magnetized, serves to attractl a vertically mounted armature 16. This armature is'provided with an adjustable coiled spring 17, which tends to hold the lower end of armature 16 away from winding 15, Armature lqcarries at its lower end 'an insulating strip on'whieh is mountedthe wedge shaped contact member 11 of the main or heater switch. When the armature moves inward or outward under the action of winding 15 or spring 17, the main switch willthereby be closed or opened. Below the mainswitch is a second armature-18, pivotally mounted, and provided with an adjustable spring 19 which tends to force theend of the arma-ture upward against the lower end of armature '16. This second armature has an upstanding lug or catch 20 which engages with the side of armature 16 and serves to hold that armature close to its winding, thereby holding the main switch closed. A winding .21 is arranged o'n the face of panel 2 with its axis vertical and with its magnetic core in position to draw down on the/holding armature 18. f

In addition to the main switch'co'ntrolling the current to the heater. winding 8, switches are provided' for controlhng the current to windings 15 and 21, these switches being. numbered respectively 22 and '23.

upward through the action of its spring .19,

switch 22 will be opened-and the current through winding 15 willl Ibe interrupted.l

Switch 23 is so disposed that it can be opened through the action of an insulating lug 25.

which is carried at -the lower end of the armature 16 and'moves therewith.

The operation of the system .above described is as follows: Current entering through distributing conductor 7 may pass directly to the heater winding 8 and then through the main switch to distributing conductor 6. It is this current which serves to heat the oven or incubator tothe desired temperature. A pilot lamp 26 of high resistance may be inserted in shunt to this heater, ifdesired, to show the voltage conditions at the heater, or to indicate when the heater is on or ofi'. After the heater has raised the temperature ofthe oven or incuv bator to the desired value, the heat will act on thermostat 12, warping it over into such position that contact will be made at 14. Current will then besent from distributing conductor 7 through the thermostat and down to winding 21 and thence through the auxiliary switch 23 and plate 24 to lamp 27.,

and finally to the other distributing conductor 6. Lamp27 serves as a resistance to protect the windings of the relay; simultaneously, it serves as an indicator of the current conditions in the relay. The current flowing through winding 21 pulls down on the holding device 18, thereby unlatching the lower end of armature 16 and allowing it to swing upward; thisl opens thev main switch 11. Simultaneously, the outward movement of armature 16 opens switch 23 and interrupts theow of current throu h winding 21, while' at the k(same, time t e downward, movement of armature 18 closes switch 22 and utsjthe systemin such condition that on t e return swing ofthe thermostat, the relay lwillbe` ready to receive current Athrough winding 15., The main switchA remains open only-lon enough to bring the temperature back to aout normal, and. thereuponthermostat 12 swings over and establishes contact at 13,' current ows through windin 15,` and lmain switch 11'reestablishes the ow of current through the heater `8.. Almost instantly the switch 22 cfpens and switch 23 closes. This places the several parts in the relative positions shown in Fig. 1.- v

It will be seen that the thermostat and its cooperating relay are-in a circuit which shunts the main or heater circuit, and-it will lbe noticed furthermore, that the How' of current through winding 15 or winding 2l inasmuch as the current flowing thr..

the thermostat is interrupted by one of t e auxiliary switches immediately after the establishment of that current at the `thermostat, there is no breaking of current at the thermostat and noA destructive arcing at its contact points. The thermostat can therefore be of deiicateiconstruction and adjustment.. i.

rEhe construction illustrated diagrammatically in Fig. 4 is the same as that illustrated in l? ig. y1 except for the addition of another heater 28, which is' connected directly across the distributing conductors 6 and 7 and thus is constantly in circuit irrespective of the manipulations of the main switch. This winding 28 is intended to heat'the oven or incubator to a temperature only a few degrees Vbelow normal temperature, reliancel being piaced on the rwinding 8 to supply some additional heating, thereby eifectlng such regulation as may be necessary to maintain substantially within the oven or incubator.

What I claim as new and desire to secure by Letters Patent of the United States is tion, a winding for tripping said holdin means, means for delivering current to sai constant temperature' electromot-ive device and to said tripping winding to move said switch and, means for limiting the flow of current through said electromotive device and through said trip- Y ping winding to currents of short duration.

2. A heating system comprising, in combination, an electric heater, a switch in cir- Cuit with said heater, la thermostat exposed to heat from said heater,- a windin connected to receive current through said t ermostat and having an armature adapted to close said heater switch, said armature having a spring effective for opening said switch,

means for holdingsaid switch in closed position, a winding arranged for tripping said holding means, said tripping winding being connected to said thermostat,l and an a iary switch in circuit with each of said windings and movable automatically wheii said heater switch moves.

3. A. heating system comprising, in com"- bination, anl electric heater, a switch in circuit with said heater, a thermostat exposed to heat from said heater, a winding receiving current through Asaid thermostat and .having a spring-pressed armature arranged to openv and close said heater switch, means for l holdand said windin shunts the electrlc heater and its switch.

^' pole of sai 4. The combination, with a thermostat of a relay coperatively related therewith, said relay havin a winding connected with one thermostat, and -an .armature movable toward said windin when the current flows through said win ing, means for holding said armature close to said winding,

a second winding connected with the other pole of said thermostat and in position to a switch to said conductors, a thermostat trip said holding means, a,switch,in circuit with each of said windings,. one of said switchesbeing arranged to open when said armature is attracte by its winding and the otherlof said .switches being adapted to open when said armature moves away trom as winding.

l 5. The combination of distributing con-` ductors, an electric heater connected through heated by said electric heater, a winding adapted to receive current through said thermostat and having an armature for closinlg 'said switch, means for holding vsaid switc in closed position, a winding for tripping said holding-means, said tripping windinlg being connected to receive current throng saidthermostat, and an auxiliary switch for 'each of said windings, each of said auxiliary switches bein movable automaticall .to

open the circuit through its winding a movement of said heater switch.

,6. The combination of distributing conductors, an electric heater connected through a switch to said conductors, a thermostat heated by said electric heater, a winding connected to receive current lthrough said thermostat, an armature lpivoted in position to be attracted b said winding when current flows therein, sald armature carrving 'a con- 'tact member of said switch, a spring tending to force said armature away from said winding to thereby open said switch, means for tion, a second winding V,connected to receive current through said thermostat and posi- 'holdingI said armature in its attracted posif50 tioned to attract said holding meanswhen' current Hows in said'winding, an auxiliary switch for each yof said windings, one of saidauxiliary switches moving in and out in conformity with the movement of said armature and the other of said auxiliary A switches being movable in unison with the movement of'said holding means.

In witness whereof I have hereunto su`b.l scribed my name, this 24 da of June 1911.

WILLIAltg1 J. SMITH.

Witnesses:

C. M. McCoNN,

EDWARD BAn'row. 

